Apparatus for producing bonded fibrous glass mats



Nov. 18, 1958 w. G. COLE, JR

APPARATUS FOR PRODUCING BONDED FIBROUS GLASS MATS Filed June 6, 1955 2 Sheets-Sheet l INVENTOR. WILLIAM CoLE J\2.

73y 1 ATTOEMEY- mutbu Nov. 18, 1958 w. e. COLE, JR 2,350,637

APPARATUS FOR PRODUCING BONDED FIBROUS GLASS MATS Filed June 6, 1955 2 Sheets-Sheet 2 INVENTOR. Wuumm COLE.,JK2.

omqvolm A TTORNEYS United States Patent APPARATUS FOR PRODUCING BONDED FIBROUS GLASS MATS William G. Cole, Jr., Nashville, Tenn., assignor to Ferro Corporation, Cleveland, Ohio, a corporation of Ohio Application June 6, 1955, Serial No. 513,463

Claims. (Cl. 154-1) This invention relates generally to a method and apparatus for producing bonded mats of glass fibers and refers more particularly to improvements in the equipment employed to deposit or lay down fibrous glass.

An object of the invention is to provide an efficient apparatus for depositing glass fibers to form mats of controlled thickness and density.

Another object of the invention is to produce a felted product of fibrous glass having not only mass integrity and tensile strength but which is also flexible and resilient.

Another object of the invention is to provide means for using resins for binding fibrous glass into a bonded mat with the foregoing characteristics.

Other objects will appear as the description proceeds.

To the accomplishments of the foregoing and related ends, the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

The present invention provides a practical apparatus and method for felting chopped strands of fibrous glass, which method includes blowing the chopped strands onto a foraminous conveyor through a reciprocating discharge head arranged to traverse across the width of the screen and means for providing a suction beneath the screen whereby the chopped strands accumulate and are evenly distributed over the surface of the screen and compacted thereon by the force of the blast from the discharge head and the suction beneath the screen.

Referring to the accompanying drawings:

Fig. 1 is a side elevation view of one form of apparatus embodying the principles of the present invention;

Fig. 2 is a plan view of the apparatus illustrated in Fig. 1;

Fig. 3 is a fragmentary sectional view of a portion of the apparatus illustrated in the previous figures, showing somewhat more specifically the manner in which the chopped strands are moved into the machine; and

Fig. 4 is a diagrammatic representation of the manner in which a single strand or roving may be withdrawn from the ball in which it is received and then fed into the cutting apparatus for the purpose of severing it preliminarily to being fed to the machine illustrated in the previous figures.

Referring now more specifically to thedrawings and more especially to Fig. 1, the apparatus here illustrated is generally divisible into two parts wherein the part indicated at 1 is, for convenience, called the chopping and feeding equipment and the equipment generally indicated at 2 is conveniently called the mat forming equipment.

As previously indicated, the equipment and method comprising the present invention utilizes fibrous glass which is available in the form of 'balls of rovings or strands generally indicated at 3 from which 'a continuous strand or roving generally indicated 4 is withdrawn 2,860,687 Patented Nov. 18, 1958 through a guide eye 5 and then preferably over a plurality of bars or rods 6, 7, 8 and 9 which are so arranged relative to each other and the path of movement of the strand or roving that the latter is caused to be flexed in opposite direction to break up the unity thereof so that as the strand or roving is then finally chopped into short lengths there will be a greater possibility for the formation of at least substantial amounts of monofilaments as the chopped mass is fed on to the web Where it is compacted into the sheet.

The thus flexed strand passes through eyes 10, 11, 12 into a cutting zone generally indicated at 13. Any suitable type of cutting apparatus may be used although for many purposes it is preferred to use a hammermill type cutter which, as is well known to those familiar with the art, consists of a plurality of knives or cutters which, when rotated, concurrently beat and thus draw the strand into the chopping equipment and then the strand is severed into sections of predetermined length. At this point it should be noted that for best results I prefer to utilize chopped roving which has been broken up sufficiently so that after being ejected by the cutting or chopping machine a substantial proportion, if not all, of the body of the mat is made up of monofilaments instead of groups of undisintegrated rovings, although the presence of some rovings which have not been reduced to monofilament sub-division can be tolerated. It is to be noted that if it is desired, by the operator, the breaker arms 6, 7, 8 and 9 can be bypassed and a mat produced which is predominately of chopped rovings or strands rather than monofilaments.

The apparatus illustrated in the drawing has been utilized in the commercial production of mat ranging in width of from 30 inches to 52 inches. In order to produce a mat of such width which weighs, for example, from 0.3 to 6 ounces per square foot and with the web on which the mat is formed traveling at a speed of about 12 to 15 feet per minute, 10 to 14 separate rovings are chopped simultaneously and fed to the machine in order to produce a two ounce mat. Thus, as for example, illustrated in the upper left-hand corner in Fig. 1 I have indicated at 14 a chopping machine which simultaneously chops seven rovings and deposits the choppings into a hopper generally indicated at 15.

The hopper 15 leads downwardly through a conduit 16 into the feed conduit 17. As most clearly illustrated in Fig. 3 adjacent the juncture of coduit 16 and 17 I may provide a venturi-type nozzle 18 which delivers a blast of air for the purpose of entraining and moving the chopped product from the conduit 16 in and through the conduit 17.

The next operation to be performed is to evenly distribute this stream of chopped fibers uniformly over the width of a continuously moving belt or web on which the mat is formed. The web or conveyor on which the mat is formed is most clearly illustrated at 19 in Fig. 1, being trained about faced pulleys 20 and 21, the latter being driven as by means of a belt 52 fro-m a prime mover 53.

At the point 17A the conduit 17 is provided with a flexible section which makes it possible for the forward portion 178 to be moved laterally to the several dottedline positions illustrated in the plan view Fig. 2.

The thus forwardly and laterally displaceable section 17B of the conduit 17 is supported from an overhead rail 22 which, at its inner end 23, is pivoted on the upper end of a vertical shaft 24. The forward end 2:5 of the rail 22 extends telescopically into a head 26 which is provided with a shoe 27 supported for lateral movement on spaced rails 28. The tube 17B is supported from the rail 22 by means of hangers 29 spaced longitudinally of the tube 17B. The forward or outer end 30 of the tube 17B is turned down much like an elbow so that the stream of chopped fibrous glass is delivered downwardly.

In order that there may be" delivered downwardly with the; streamaof fibrous glass delivered by tliel tube-17B; a suitable binder therefor; there -is-provided-a conduit generally indicated at 31 which leads from a hopper or reservoir, not-shown, for a suitable bonding resin-such asa polyester andthis conduit 31 overlies the conduit 17718 as at 32 and at its forward end is-provided with a Y-shaped discharge head formed of sections 33 and 34 by which the-stream'of polyester resin is divided and discharged downwardly on opposite sides ofthe downwardly discharge stream of chopped fibrous glass: As for the resinsusable in making mat oathe-present apparatus both thethermo-setting resins such as phenolics, melamines, polyesters, etc. and the thermoplastic resins, such as, modified polyesters, polyvinyl acetate, polystyrene, etc. can be used While not shown in the drawing,

it is within the contemplation of the invention'to utilize nozzles and the like for the. purpose of effecting a breakup of the stream of bonding resin and to direct such stream into'the downwardly falling stream of chopped fibrous glass.

The downward blast of the two streams of resin and the downward blast of the stream of'chopped fibrous glass entrained in air so intermix that before the choppedglass fibers are depositedto form the mat, the individual components, that is the monofilaments are completely surrounded with the bonding resin.

As previously indicated it will be understood that the chopped fibrous material will be discharged downwardly directly on to the surface of the mat-forming web 19. In orderto render such deposit uniform, it is preferable that the forward end 17B of the conduit for the fibrous glass be oscillated back and forth between the dottedline positions A and B on Fig. 2. Any suitable drive means may be provided for this purpose and, since such means are so simple and well-known, they have been omitted from the drawing for the purposes of clarity.

in order to laterally confine the stream of fibrous glass and the streams of resin as they are projected downwardly on to the mat-forming web 19, there is provided a lateral enclosure generally indicated at 35 which extends from a point just above the lower end of the conduit 17B to a point just above the'web 19. Thus, as the downwardly projecting stream of glass and the bonding resins is laterally confined, the course of impingement thereby on to the web-forming mat is increased with a corresponding increase in the felting effects of the stream.

In order to further increase the felting of the mat in the early stages of its formation, the web or conveyor 19 passes over a suction box generally indicated at 36 which is arranged in the area directly below the area within which the glass is deposited on the foraminous web 19. The lateral configurationuof the suction box 36 is preferably substantially the same as the lateral extent of the confining walls 35 within Which the glass and bonding resin streams are led on to the web 19.

The lateral extent of the suction box 36 and the confining walls 35 is difiicult to show on the drawings because of the presence of the other equipment. However, by having reference to plan view Fig. 2 it will be observed that the meets and bounds of the lateral wallsof the suction box and the confining chamber are the four corners 37, 38, 39 and 4-0.

in order to provide suction in the suction box 36 a conduit indicated in dotted lines on Fig. 2 at 41 extends laterally to a suction fan generally indicated at 42 which is driven by a motor 43 and the exhausted air sent upwardly through a stack 44..

As previously indicated the web 15 trained about pulleys 2t) and 21 moves from right to left in its upper run in Figs. 1 and 2 at a speed of approximately.5 to 25 feet per minute and in this way the preliminarily felted glass mat formed over the suction box 36 is carried to the 'left' for a series" of further'treatm'ents'. The "first of these treatments is the application thereto of additional bonding material which may be applied through the trough 45 which extends transversely of the machine and has its discharge slot along the bottom closely ad'- jacent the top of the mat; This is done so that the mat comprises about 4%l0% resin per of chopped fibers. Suitable means such as'a screw conveyor, not shown, or the like may be used for the purpose of feeding to the trough 45 the bonding material which,'as previously indicated, may be'in the form of a dry resin. If, of course, a different type of bonding material such as a liquid were to be used, correspondingly different feed means would need to be employed.

The thus formed and preliminarily felted mat continues moving to the left on the upper run of the conveyor web 19 until it reaches the area generally indicated at 46 where the mat is sprayed from opposite'sides' through a series of nozzles47 and 48with a suitableliquitlfor" which purpose wateris quite satisfactory. The 'effect'of' this liquid application is to furtherdensify oncompact the mat,-so thatbetter bondis obtained betweenthe felted fibersduring the curing process in' the oven. At-- tention is directed to the fact-that if desired instead' of spraying water'through fog nozzles47 and 48 water emulsions of various resins may be used.

The web 19 discharges the thus formedrnat onto an auxiliary conveyor 49 which in turn discharges on to a treating conveyor 50; the latter being preferably'formed of metal and foraminous' in character and which carries themat into the feed'end of a curing oven generally indicated at 51 within which the mat is subjected to a temperature such as to fix the resin and thoroughly bond the mat.

also in the oven '51.

The foregoing apparatus and method produces 'a inat extremely uniform in weight, thickness an'd'color.

Other modes of applying the principle of the invention may be employed, change being made'as regards the details described provided the featurestated in any of I, therefore, particula'rlypoint 'outa'nd distinctly claim' as my invention:

1. In an apparatus for producing" a feltedmat of chopped fibrous glass, the combination comprising, a movable foraminous planular conveyor, a confining'guide member having an open end movably supported for discharge against one side of said planular conveyor, jet means for directing a stream of fluid through said guide member, means for feeding short lengths of fibrous glass into the fluid jet stream in said guide member for discharge through the open end against said one surface of the conveyor, means for reciprocating the open end of said guide member across said one surface of the conveyor and transverse to the direction of the conveyor movement, andsuction means disposed adjacent the opposite surface of said planular conveyor for coacting with said discharged fibrous glass to provide a felted mat of fibrous glass on said one surface of the conveyor having substantially even distribution and uniform density.

2. Theapparatus of claim 1 wherein said means for feeding short lengths of fibrous glass includes, means for supplying continuously stranded fibrous glass thereto, other means for locally engaging and reversely bending the 'stranded fibrous glass, and cutting means for locally engaging and chopping the reversely bent stranded fibrous glass into shortaxial lengths. A

3. In an apparatus for producing a felted mat of chopped fibrous glass the combination'comprising, a movable foraminous planular conveyor, a confining guide member having one open end movably supported for discharge of its pontents against one side of said planular The water whi'ch'had been introduced to the" mat at nozzles 47 and 48' "is, 'of course, evaporated conveyor, jet means for directing a stream of fluid through said guide member, means for feeding short lengths of fibrous glass into the fluid jet stream in said guide member for discharge through the open end against said one surface of the conveyor, means for introducing a stream of resinous bonding material into the discharged stream of chopped fibrous glass at the point of dicharge to commingle the streams, means for reciprocating the open end of said guide member and said bonding material discharge means across said one surface of the conveyor and transverse to the direction of conveyor movement, and suction means disposed adjacent the opposite surface of said planular conveyor for coaction with said discharged fibrous glass and bonding material to provide a felted mat of bonded fibrous glass on said one surface of the conveyor having substantially even distribu tion and uniform density.

4. In an apparatus for producing a felted mat of chopped fibrous glass the combination comprising, a movable foraminous planular conveyor, a confining guide member having an open end movably supported for discharge of its contents against one surface of said planular conveyor, means for directing a jet stream of fluid through said guide member, means for feeding short axial lengths of fibrous glass into the fluid jet stream in said guide member for discharge through the open end against said one surface of the conveyor, means for reciprocating the open end of said guide member across said one surface of the conveyor and transverse to the direction of conveyor movement, means located in spaced relation along the conveyor from the point of discharge of fibrous glass and in the direction of conveyor movement for directing fibrous bonding material onto said mat, and suction means disposed adjacent the opposite surface of the planular conveyor at the point of fibrous glass discharge for coacting with said discharged fibrous glass to provide a felted mat of fibrous glass on said one surface of the conveyor having substantially even distribution and uniform density.

5. In an apparatus for producing a felted mat of chopped fibrous glass the combination comprising, a movable foraminous planular conveyor, a confining guide member having an open end moveably supported for discharge of its contents against one surface of said planular conveyor, means for directing a jet stream of fluid through said guide member, means for feeding short axial lengths of fibrous glass into the fluid jet stream of said guide member for discharge through the open end thereof and against said one surface of the conveyor, means for reciprocating the open end of said guide member across said one surface of the conveyor and transverse to the direction of conveyor movement, suction means disposed adjacent the discharge of fibrous glass to provide a felted mat of fibrous glass on said one surface of the conveyor having substantially even distribution and uniform density, means for discharging the mat at the other end of the conveyor, and other means for receiving and curing the felted mat.

References Cited in the file of this patent UNITED STATES PATENTS 2,457,784 Slayter Dec. 28, 1948 2,500,665 Courtright Mar. 14, 1950 2,571,334 Browne Oct. 16, 1951 2,577,205 Meyer et a1 Dec. 4, 1951 2,584,702 Hogendobler Feb. 5, 1952 2,619,151 Sheidley Nov. 25, 1952 2,653,355 Essman Sept. 29, 1953 2,702,261 Bacon et a1 Feb. 15, 1955 

